Improving Code Word Interference Cancellation (CWIC) Technique in Heterogeneous Network
This paper first examines performance of (code word interference cancellation) CWIC for downlink non orthogonal multiple access (NOMA) combined with 2-by-4 multi-user (MU)-MIMO, taking into account the disadvantages of the CWIC receiver, such as complex receiver structure, high volumes of network overhead and high delay, we offer a way to improve the efficiency of the CWIC receiver. CWIC receiver detects, decodes and cancels all interference signals in several steps, from large to small, respectively. The number of interference cancellation stages depends on the number of interference signals. The proposed receiver only cancels the intense interference signal. That's why it's called CWIC-II (Intense Interference). Finally, using simulation, we show that CWIC-II receiver reduces latency and improves throughput. The complexity problem of the CWIC receiver structure is also resolved. In the end, a method has been developed to resolve the problems of the proposed receiver.
 D. Lopez-Perez and et al., “Enhanced Inter-cell Interference Coordination Challenges in Heterogeneous Networks,” IEEE Wireless Communications, vol. 18, no. 3, pp. 22– 30, 2011.
 A. Damnjanovic, J. Montojo, Y. Wei, T. Ji, T. Luo, M. Vajapeyam, T. Yoo, O. Song, and D. Malladi, “A survey on 3gpp heterogeneous networks,” IEEE Wireless Communications Magazine, vol. 18, no. 3, pp. 10–21, 2011.
 K. Saito, A. Benjebbour, Y. Kishiyama, Y. Okumura and T. Nakamura, “Performance and design of SIC receiver for downlink NOMA with open-loop SU-MIMO,” in Proc. IEEE Int. Conf. Commun. Workshop (ICCW), London, Jun. 2015, pp. 1161-1165.
 Q. H. Spencer, C. B. Peel, A. L. Swindlehurst, and M. Haardt, “An introduction to the multi-user MIMO downlink,” IEEE Commun. Mag.vol. 42, no. 10, pp. 60–67, Oct. 2004.
 Liao, CH, Morikawa, “H. Latticing the interference: non-linear pre-coding for non-orthogonal multiple access in downlink multi-user MIMO system”. IEEE 26th Annual International Symposium on (PIMRC). pp.710–714. 03 December 2015.
 X. Sun, N. Yang, S. Yan, Z. Ding, D. W. K. Ng, C. Shen, and Z. Zhong, “Joint beamforming and power allocation in downlink NOMA multiuser MIMO networks,” IEEE Trans. Wireless Commun., Early Access, Jun. 2018.
 3GPP, “TS 36.814 Further Advancements for E-UTRA Physical Layer,” Mar. 2009.
 G. Morozov, A. Davydov, “Decoding-aided parameter estimation for interference cancellation and suppression receivers in lte-advanced systems”, IEEE Vehicular Technology Conference (VTC Spring), pp. 1-5, 2015.
 D. Tse and P. Viswanath, Fundamentals of Wireless Communication. Cambridge University Press, 2005.
 3GPP, TS 36.211 (V8.9.0), “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation (Release 8),”Dec. 2009.
 Saito K, Benjebbour A, Harada A, Kishiyama Y,Nakamura T. “Link-level performance of downlink NOMA with SIC receiver considering error vector magnitude”, 2015 IEEE 81st Vehicular Technology Conference (VTC Spring), pp.1–5, 02 July 2015.